RavenclawDev: returning frame from a back end

[Svetlana Stenchikova]

Do you think it is possible to return a structure from a java back-end in a
format expected by RavenClaw?

If so, could you please recomment how, and if not, could someone point to
the place in RavenClaw that I could modify to work around this issue?

I am sorry to bother you with this question, but we have a demo coming up
and listing the events is one of the essential functionality that we wanted
to show.

Thank you all for your help!

Svetlana

On 10/10/06, Svetlana Stenchikova <svetastenchikova at gmail.com> wrote:
>
> Thanks Dan,
>
> this generally makes sense, but I am not sure how to do this in the java
> server.
>
> The operation function in the java galaxy service returns a GFrame.
>
> I can set properties of this frame in any way, but I must return a GFrame,
> I think. I tried declaring an operation that returns String and it causes
> runtime exception:
> java.lang.ClassCastException: java.lang.String
>
>
> This is how a RoomLine return from a perl back end looks like:
>
> {
>         suggested_refine        none
>         error   false
>         results :1
>         {
>                 {
>                         date_time       {
>                                 time    {
>                                         start_time      1700
>                                         end_time        1800
>                                 }
>                                 date    {
>                                         valid_date      true
>                                         year    2006
>                                         month   10
>                                         day     11
>                                         weekday 3
>                                 }
>                         }
>                         room_size       30
>                         room_projector  true
>                         room_whiteboard true
>                         room_computer   true
>                         room_network    true
>                         room_location   Wean Hall
>                         room_size_spec  large
>                         room_number     4625
>                 }
>         }
> }
>
>
> And here is how my java back end frame looks like:
>
> Server environment sending frame:
> {c java_be.add_event
>    error "false"
>    :hub_opaque_data {c admin_info
>                        :reply_requested 1
>                        :session_id "Default"
>                        :tidx 70
>                        :scriptless 1
>                        :timestamp [array: type GAL_FLOAT_64, 1 elements]
>                        :provider_id "[8]"
>                        :invoked_stype "java_be" } }
>
> Please make a suggestion on how to return a string from a java server.
>
> thank you,
> Svetlana
>
> On 10/10/06, Dan Bohus <dbohus at cs.cmu.edu> wrote:
> >
> >  Hi Svetlana,
> >
> >
> >
> > I think this is the same problem with "Ravenclaw frames" and "galaxy
> > frames" but on the output side. Basically what you're doing in the code
> > below is constructing a galaxy frame. Instead ravenclaw expects a single
> > string in that galaxy frame which contains the information in a single
> > string in the "string Ravenclaw frame" format…
> >
> >
> >
> > If this message is too cryptic, let me know and I can send you more
> > details,
> >
> > Dan
> >
> >
> >  ------------------------------
> >
> > *From:* ravenclaw-developers-bounces at LOGANBERRY.srv.cs.cmu.edu [mailto:
> > ravenclaw-developers-bounces at LOGANBERRY.srv.cs.cmu.edu] * On Behalf Of *Svetlana
> > Stenchikova
> > *Sent:* Tuesday, October 10, 2006 5:41 PM
> > *To:* ravenclaw-developers at cs.cmu.edu
> > *Subject:* RavenclawDev: returning frame from a back end
> >
> >
> >
> > Hi,
> >
> > How should a  back-end function of a ravenclaw dialog manager format a
> > frame?
> >
> > For example,  I am expecting to get a "error" parameter from:
> >
> > CALL("java_be.add_event <event_add error>backend_error")
> >
> > backend_error is declared as:
> > BOOL_SYSTEM_CONCEPT(backend_error)
> >
> > In the java back-end:
> >
> > public GFrame serverOpAddEvent(GFrame f) {
> > ...
> >
> >     GFrame eventAdded = new Clause("event_add");
> >
> >     eventAdded.setProperty("error", "false");
> >
> >     return eventAdded;
> > }
> >
> >
> > But the backend_error in DM does not get initialized.
> >
> > Is there a particular way that the return GFrame from the backend server
> > has to be generated?
> >
> > Thank you,
> > Svetlana
> >
>
>
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